Add check for unstable spring parameters

src/spring.luau

@@ -161,6 +161,11 @@ local function spring<T>(source: () -> T, period: number?, damping_ratio: number
     local c_c = 2*w_n
     local c = z * c_c
 
+    -- todo: is there a solution to this other than upping step frequency?
+    if c > UPDATE_RATE*2 then -- solver will explode if this is true
+        throw("spring damping too high, consider reducing damping or increasing period")
+    end
+
     local data: SpringData<T> = {
         k = k,
         c = c,

test/spring-test.luau

@@ -48,14 +48,14 @@ local function main()
         local reset = "\27[H\27[2J" -- ANSI clear terminal
         local offset = string.rep("\n", MAX - fv + OFFSET)
         local bar = testkit.color.gray(remainder_to_block(v - fv) .. "\n" .. string.rep(BLOCK .. "\n", fv))
-        print(reset .. offset .. bar)
+        print(reset .. offset .. bar .. "\n" .. v)
     end)
 
-    local elapsed = 0
+    local T = 3
+    local elapsed = T/1.2
     repeat local dt = step()
         vide.step(dt)
 
-        local T = 3
         elapsed += dt
         while elapsed >= T do
             elapsed -= T